Mechanism for actuating clutches and the like



Why 21,- 1946. I A. McMlLLAN MECHANISM FOR ACTUAT ING CLUTCHES AND THELIKE Filed Dec. 20, 1943 grvvq/rvtqb ANDREW McMILLAN,

Patented May 21, 1946 MECHANISM FOR ACTUATING CLUTCHES AND THE LIKEAndrew McMillan, Milwaukee, Wis., assignor to Chain Belt Company,Milwaukee, Wis., a corporation of Wisconsin Application December 20,1943, Serial No. 515,015

3 Claims.

The invention relates to mechanism for actuating clutches and the like,and while it may find other applications, for purposes of disclosure ithas been illustrated and will be described in the environment for whichit has been primarily designed, viz., control of the skip clutch of aconcrete mixing machine.

It is customary in such machines toelevate and lower the skip (by meansof which batches of concrete making materials are charged into themixing drum) by means of hoisting mechanism including cables and windingdrums therefor, which drums are driven through appropriate mechanismfrom the mixer motor. Usually such motor drives a continuously rotatingcountershaft from which power may be taken at will through frictionclutches to rotate the mixing drum and to drive various otherinstrumentalities of the machine, including the skip cable winding drum,

One of the objects of the present invention is to provide mechanismwhich, while under the manual control of the operator, will effectactual shifting of a clutch, such as that for the skip cable windingdrum, by power supplied by the motor.

One form of the apparatus is disclosed in the accompanying drawingforming a part of this specification, in which like referencecharactersdesignate like parts in allthe views, and in which:

comprises a framework Ill, mounted for ground traverse upon crawlertreads H, and having a mixing drum l2 mounted within it for rotationupon rollers [3. A motor I4 is mounted upon the said framework I and,when operating, continuously rotates a countershaft I5 through a speedreducing drive, not shown. A skip [6, for charging materials into thedrum I2, is pivotally mounted on the frame Ill at I I and is adapted tobe elevated to and lowered from drum-charging position by cables l8passing over sheaves I9 and 'wound upon drums carried by a transverseshaft 2!. This shaft is-adapted tobe rotated by a bull wheel 22 uponwhich is wound a cable 23,.

which passes to and is also wound upona winding drum 24, here shown asloosely mounted upon the countershaft l5 and adapted to be clutchedthereto by a friction clutch 25 having a shifting Figure 1 is a more orless diagrammatic side elevational view of a portion of the elements ofproximately on the plane indicated by the line 4-4 of Fig. 2, looking inthe direction of the arrows; and

Fig. 5 is an enlarged sectional-elevational view, approximately on theplane indicated by the line 55 of Fig. 1, illustrating the manualcontrol lever for the shifting mechanism, and its mounting andconnections.

The concrete mixing machine shown in Fig. 1

collar 26 associated therewith.

The parts thus far referred to are all conventional in this type ofmachine, and are here more or less diagrammatically shown.

The mechanism for shifting the clutch 25 to couple the drum 24 to theshaft l5, whereby the skip l6 may be raised, comprises a supportingmember or bracket 30, which may be suitably mounted on the'machine frameIn in juxtaposition to the. said shaft, asillustrated in Fig. 1. Thebracket member 30 includes a pair ofspaced upstanding plates 3| and 32which mount a horizontal rod 33 which serves as a support and guide fora block 34 whichis slidably mounted thereon. This block is provided witha pair of trunnions 35 which constitute the fulcrum of anupwardlyextending lever 36, which is connected at 31 to a link 38 which in turnis connected at 39 to a shifting yoke 49, pivoted as at 4| and engagingpins 42 carried by the clutch-shifting collar 26. A cam 43 isrigidlymounted on the shaft I5 adjacent the winding drum 24,. and thelever 36 carries a follower roller 44 positioned for co-operation withthe cam, as will appear more fully below.

The trunnions 35 of the block 34 also pivotally receive one end of apair of links 45, the other ends of which are pivotally connected as at46 to an arm 4'! of a bell-crank lever 48, pivoted as at 49 between apair of longitudinal ears 59 which may extend from the transverse plate32.

The other arm 5! of the bell-crank lever 48 has.

one end of a wire or cable 52 connected to it at 53, which wire or cableextends through a housing or sheath 54 upwardly to the operatorsstation, adjacent the forward end of the mixing drum [2. The framefrequently includes a protective panel 55 for shielding the drum and thewire or cable 52 may extend up behind this panel to a control box orhousing 56 formed in or carried by the panel. In this housing a controllever 51 is mounted on a shaft 58 which also carries an arm 59 to whichthe upper end of the wire or cable 52 is connected as at 60.

The bracket is provided with a stop member 6| so disposed as to beengaged by the arm 41 as it reaches the position shown in Fig. '3. Inthis position the pivot 46 has passed slightly below the dead-centerline between pivots and 49, and the said engagement between the arm 4'!and stop 6| therefore serves to lock the block 34 in the Fig. 3 positionwhereby its trunnions 35 may serve as a fixed fulcrum for the lever 36.The roller 44 carried by the said lever may thus be retained inoperative relation to the cam 43 withoutthe necessity of the operatorholding the control lever 51 in the broken line position of Fig. 5.

As above indicated, the normal position of the ,parts is thatillustrated inFigs. 1 and 2. When it is desired to raise the skip IS,the operator merelymoves the control lever 5'! from the full line to thebroken line position of Fig. 5 which, through arm 59, cable 52,bell-crank lever 48 and links 45, draws the block 34 along the guide rod33 to the position illustrated in Fig. 3. During this movement the lever36 pivot on the link connection 3'! to assume the position illustratedin full lines in Fig. 3, and its roller 44 is moved ing of the clutch isperformed mechanically by power derived from the motor 14, and sinceunder present day paving practice it may be necessary to elevate theskip every to '70 seconds, and since this is only a portion of theoperators duties, the present mechanism provides appreciable relief forhim.

While one form of the invention has been illustrated and described, itwill be obvious that those skilled in the art may vary the details ofconstruction as well as the precise arrangement a bracket structurehaving a guide; a block slidinto operative relation to the cam 43. Theshaft I5 and cam 43 are continuously rotating at a relatively low speed,say to R. P. M., and as the high portion of the cam engages the roller,the latter together with the lever 36 will be forced .to the broken lineposition of Fig. 3, which move ment through link 38 and shifting yoke 40will shift the clutch 25 to engaged position and couple the winding drum24' to the shaft l5. The cable 23 will thus be wound upon the said drum,

and unwound from the bull wheel 22, rotating the latter and with it thewinding drums 20, winding the cables l8 thereon and elevating the skip.As is well known to those skilled in this art, mixing machines of thistype are ordinarily provided with an automatic clutch knock-out (nothere shown) actuated by the skip as itreaches its discharge station, andas therclutch is of a type which will remain engaged until suchknock-out occurs, the operator may return the control lever 51 to itsnormal full line positionas soon as the skip starts up. Such return willrestore the block 34 to its Fig. 2 position, the lever 36-pivoting aboutthe link connection 31 (in its broken line position of Fig. 3) andmoving roller 44 out of operative relation to the cam 43. When theautomatic clutch knock-out occurs, the parts will be fully restored tothe Fig.2 position, with roller 44 still out of operative relation tothe cam.

Whilethe control is manual, the actual shiftably mounted on said guide,providing a shiftable fulcrum for said lever; a bell crank mounted onsaid bracket structure and connected to said block; and a manuallyoperable control member connected to said bell crank for causing thelatter to slide the block on the guide and move the lever and followerinto operative relation to the cam whereby it may swing the lever on thefulcrum and actuate the clutch shifting element.

2. In mechanism'for actuating a clutch shifting element; a power-drivencam; a lever connected to said shifting element and provided with afollower for engagement with said cam; a bracket structure having aguide; a block slidably mounted on said guide, providing a shiftablefulcrum for said lever; a bell crank mounted on said bracket structure;links connecting said block to one arm of said bell crank; a manuallyoperable remotely located control member; and a cable connection betweensaid control member and the other arm of said bell crank, whereby thelatter may be caused to slide the fulcrum block and move the lever andfollower into operative relation to the cam, where the latter may swingthe lever on the fulcrum and actuate the clutch shifting element.

3. In mechanism for actuating a clutch shifting element, a power drivencam; a lever connected to said shifting element; a supporting member;means slidably mounted on said member providing a bodily shiftablefulcrum for said lever; a bell crank connected to said fulcrum means forshifting the latter uponsaid support ing member to move the lever intoposition to be engaged by the cam, whereby the latter may swing thelever upon the fulcrum and actuate the shifting element, a portion ofthe bell crank being engageable with the supporting member to provide atoggle lock for temporarily retaining the fulcrum in said shiftedposition; and manually operable means for actuating said bell crank.

' ANDREW McMILLAN.

